EXTRAGALACTIC LARGE-SCALE STRUCTURES BEHIND THE SOUTHERN MILKY-WAY - II - REDSHIFTS OBTAINED AT THE SAAO IN THE CRUX REGION

In our systematic optical galaxy search behind the southern Milky Way, 3760 (mostly unknown) galaxies with diameters D greater than or simil ar to 0.'2 were identified in the Crux region (287 degrees less than o r similar to l less than or similar to 318 degrees, /b/ less than or s imilar to 10 degrees, Woudt & Kraan Korteweg 1997). Prior to this inve stigation, only 65 of these galaxies had known redshifts. In order to map the galaxy distribution in redshift space we obtained spectra for 226 bright (B-J less than or similar to 18) objects with the 1.9 m tel escope of the South African Astronomical Observatory (SAAO). Redshifts could be determined for 209 objects, of which 173 have good signal-to -noise ratios. Of the 36 tentative redshifts, four are confirmed throu gh independent values in the literature. The redshifts of three object s indicate them to be galactic in origin. One of these confirms a susp ected Planetary Nebula. For 17 of the galaxies,no redshift could be de termined due to poor signal-to-noise ratios. In addition, 26 redshifts have have been measured in the Hydra-Antlia region investigated earli er (Kraan-Korteweg et al. 1995); of which one is a tentative estimate. Two main structures crossing the Galactic Plane in the Crux region ha ve now become clear. A narrow, nearby filament from (l, b) = (340 degr ees, -25 degrees) to the Centaurus cluster can be traced. This filamen t runs almost parallel to the extension of the Hydra-Antlia clusters f ound earlier and is part of what we have earlier termed the ''Centauru s Wall'' extending in redshift-space between 0 less than or equal to n u less than or equal to 6000 km s(-1)(Fairall & Paverd 1995). The main outcome of this survey however, is the recognition of another massive extended structure between 4000 less than or equal to nu less than or equal to 8000 km s(-1) This broad structure, dubbed the Norma Supercl uster (Woudt et al. 1997), runs nearly parallel to tile Galactic Plane from Vela to ACO 3627 (its centre) from where it continues to the Pav e cluster. This massive structure is believed to be associated with th e Great Attractor. The survey has furthermore revealed a set of cellul ar structures,similar to those seen in redshift space at higher galact ic latitudes, but never before seen so clearly behind the Milky Way.